said Houston, 41, as he began a five-city flyaround. ``I believe the people of Illinois want a state treasurer who will aggressively use the investment funds of state government to retain and create jobs in Illinois.``

Houston`s formal announcement sets up a likely GOP primary contest against Rep. Jack Davis (R., New Lenox), an assistant minority leader in the House who is expected to announce his candidacy next week.

``My feeling is that the governor will not make any personal endorsements in either the treasurer`s or the comptroller`s race,`` Houston said.

Party leaders, however, have indicated that Gov. James Thompson, hoping to solidify Republican support for his re-election, has put together a ``unity ticket`` and has urged Davis to seek the treasurer`s job.

However, Houston said: ``I`m in the race to stay. On Nov. 4, 1986, I will become the first Republican to be elected state treasurer since 1962.``

William J. Scott, later the Illinois attorney general and candidate for the U. S. Senate, was the last Republican to hold the office.

Bernard Carey, former state`s attorney in Cook County, will be chairman of Houston`s campaign. Houston said he does not have the personal wealth to fund a campaign as did John Dailey of Peoria, who won the nomination in 1982 after a primary contest with former House Speaker W. Robert Blair of Crete.

``Citizens for Houston is basically starting out with no funds,`` Houston said at a news conference in the capital.